feat: 记录删除与筛选、用户侧内容删除、AI 聊天历史

修复雪花 ID 精度丢失（真 bug）
- bottom-sheet 的 postId 声明为 Number，而 ID 是 18 位雪花字符串，
  超出 JS 安全整数范围：339346584095428608 会被转成 ...600，
  评论弹层实际查的是不存在的帖子。改为 String

记录
- 后端 DELETE /records/:id 早已就绪但前端从未调用，记错了删不掉。
  时间轴支持长按删除
- 时间轴加类型筛选（体重/便便/饮食/异常/用药/疫苗/消费/照片），
  后端 ?type= 本就支持

用户侧内容删除（UGC 合规：用户应能删除自己发布的内容）
- 新增 DELETE /posts/:id 与 DELETE /comments/:id，仅限本人，
  越权返回 40300；帖子软删除，评论删除同步递减 comment_count
- 评论列表返回 is_self；社区长按自己的帖子、长按自己的评论可删

AI 聊天历史
- ai_messages 一直在写但没有查询接口，每次打开弹层都是空白。
  新增 GET /api/ai/messages，弹层打开时接在开场白后加载

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pets-be/internal/handler/community.go

@@ -104,7 +104,7 @@ func (h *Handler) ListComments(c *gin.Context) {
 	_ = c.ShouldBindQuery(&req)
 	req.Normalize()
 
-	comments, total, err := h.svc.ListComments(idParam(c, "id"), req.Offset(), req.Limit())
+	comments, total, err := h.svc.ListComments(middleware.UserID(c), idParam(c, "id"), req.Offset(), req.Limit())
 	if err != nil {
 		response.FailErr(c, err)
 		return
@@ -152,3 +152,21 @@ func (h *Handler) UnfollowUser(c *gin.Context) {
 	}
 	response.OK(c, gin.H{"followed": false})
 }
+
+// DeleteOwnPost DELETE /api/posts/:id （仅限本人）
+func (h *Handler) DeleteOwnPost(c *gin.Context) {
+	if err := h.svc.DeleteOwnPost(middleware.UserID(c), idParam(c, "id")); err != nil {
+		respondErr(c, err)
+		return
+	}
+	response.OK(c, gin.H{"deleted": true})
+}
+
+// DeleteOwnComment DELETE /api/comments/:id （仅限本人）
+func (h *Handler) DeleteOwnComment(c *gin.Context) {
+	if err := h.svc.DeleteOwnComment(middleware.UserID(c), idParam(c, "id")); err != nil {
+		respondErr(c, err)
+		return
+	}
+	response.OK(c, gin.H{"deleted": true})
+}

pets-be/internal/handler/helper.go

@@ -27,5 +27,9 @@ func respondErr(c *gin.Context, err error) {
 		response.Fail(c, errcode.ErrNotFound, "")
 		return
 	}
+	if errors.Is(err, service.ErrForbidden) {
+		response.Fail(c, errcode.ErrForbidden, err.Error())
+		return
+	}
 	response.FailErr(c, err)
 }

pets-be/internal/handler/misc.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"errors"
+	"strconv"
 
 	"github.com/gin-gonic/gin"
 
@@ -173,3 +174,17 @@ func (h *Handler) AdminSetFeedbackHandled(c *gin.Context) {
 	}
 	response.OK(c, gin.H{"ok": true})
 }
+
+// ListAIMessages GET /api/ai/messages?session=&limit=
+func (h *Handler) ListAIMessages(c *gin.Context) {
+	limit := 0
+	if v := c.Query("limit"); v != "" {
+		limit, _ = strconv.Atoi(v)
+	}
+	msgs, err := h.svc.ListAIMessages(middleware.UserID(c), c.Query("session"), limit)
+	if err != nil {
+		response.FailErr(c, err)
+		return
+	}
+	response.OK(c, msgs)
+}

pets-be/internal/model/comment.go

@@ -8,4 +8,6 @@ type Comment struct {
 	AuthorName string `gorm:"size:64" json:"author_name"`
 	Content    string `gorm:"size:512" json:"content"`
 	Status     string `gorm:"size:16;default:published" json:"status"`
+
+	IsSelf bool `gorm:"-" json:"is_self"` // 计算字段：是不是我自己发的
 }

pets-be/internal/router/router.go

@@ -94,6 +94,8 @@ func registerUserAPI(api *gin.RouterGroup, h *handler.Handler, jm *appjwt.Manage
 	g.DELETE("/posts/:id/like", h.UnlikePost)
 	g.GET("/posts/:id/comments", h.ListComments)
 	g.POST("/posts/:id/comments", h.CreateComment)
+	g.DELETE("/posts/:id", h.DeleteOwnPost)
+	g.DELETE("/comments/:id", h.DeleteOwnComment)
 
 	g.GET("/articles", h.ListArticles)
 	g.POST("/feedback", h.CreateFeedback)
@@ -103,6 +105,7 @@ func registerUserAPI(api *gin.RouterGroup, h *handler.Handler, jm *appjwt.Manage
 	g.POST("/pro/activate", h.ActivatePro)
 
 	g.POST("/ai/chat", h.AIChat)
+	g.GET("/ai/messages", h.ListAIMessages)
 	g.POST("/pets/:id/ai/assess-symptom", h.AssessSymptom)
 	g.POST("/upload", h.Upload)
 }

pets-be/internal/service/ai.go

@@ -29,3 +29,23 @@ func (s *Service) AIChat(userID string, petID *string, session, text string) (st
 func (s *Service) Upload(objectName string, reader io.Reader, size int64, contentType string) (string, error) {
 	return s.storage.Upload(objectName, reader, size, contentType)
 }
+
+// ListAIMessages 取当前用户的聊天历史（按会话，默认最近 N 条，返回时间正序）
+func (s *Service) ListAIMessages(userID, session string, limit int) ([]model.AIMessage, error) {
+	if limit <= 0 || limit > 100 {
+		limit = 30
+	}
+	q := s.db.Where("user_id = ?", userID)
+	if session != "" {
+		q = q.Where("session = ?", session)
+	}
+	var msgs []model.AIMessage
+	if err := q.Order("id desc").Limit(limit).Find(&msgs).Error; err != nil {
+		return nil, err
+	}
+	// 反转成时间正序，前端直接按顺序渲染
+	for i, j := 0, len(msgs)-1; i < j; i, j = i+1, j-1 {
+		msgs[i], msgs[j] = msgs[j], msgs[i]
+	}
+	return msgs, nil
+}

pets-be/internal/service/community.go

@@ -192,7 +192,7 @@ func (s *Service) postLikeCount(postID string) (int, error) {
 }
 
 // ListComments 评论分页
-func (s *Service) ListComments(postID string, offset, limit int) ([]model.Comment, int64, error) {
+func (s *Service) ListComments(userID, postID string, offset, limit int) ([]model.Comment, int64, error) {
 	q := s.db.Model(&model.Comment{}).Where("post_id = ? AND status = ?", postID, "published")
 	var total int64
 	if err := q.Count(&total).Error; err != nil {
@@ -202,6 +202,9 @@ func (s *Service) ListComments(postID string, offset, limit int) ([]model.Commen
 	if err := q.Order("id desc").Offset(offset).Limit(limit).Find(&comments).Error; err != nil {
 		return nil, 0, err
 	}
+	for i := range comments {
+		comments[i].IsSelf = comments[i].UserID == userID
+	}
 	return comments, total, nil
 }
 
@@ -227,3 +230,38 @@ func (s *Service) CreateComment(userID, postID string, content string) (*model.C
 	}
 	return &comment, nil
 }
+
+// DeleteOwnPost 用户删除自己的帖子（软删除，保留数据可追溯）
+func (s *Service) DeleteOwnPost(userID, postID string) error {
+	var p model.Post
+	if err := s.db.Where("id = ?", postID).First(&p).Error; err != nil {
+		return ErrNotFound
+	}
+	if p.UserID != userID {
+		return ErrForbidden
+	}
+	return s.db.Model(&model.Post{}).Where("id = ?", postID).
+		Update("status", model.PostDeleted).Error
+}
+
+// DeleteOwnComment 用户删除自己的评论，并同步帖子评论数
+func (s *Service) DeleteOwnComment(userID, commentID string) error {
+	var c model.Comment
+	if err := s.db.Where("id = ?", commentID).First(&c).Error; err != nil {
+		return ErrNotFound
+	}
+	if c.UserID != userID {
+		return ErrForbidden
+	}
+	if c.Status == "deleted" {
+		return nil // 幂等
+	}
+	return s.db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Model(&model.Comment{}).Where("id = ?", commentID).
+			Update("status", "deleted").Error; err != nil {
+			return err
+		}
+		return tx.Model(&model.Post{}).Where("id = ? AND comment_count > 0", c.PostID).
+			UpdateColumn("comment_count", gorm.Expr("comment_count - 1")).Error
+	})
+}

pets-be/internal/service/service.go

@@ -18,6 +18,9 @@ var ErrNotFound = errors.New("not found")
 // 避免「点一下白拿会员」。
 var ErrPayNotReady = errors.New("支付功能即将开放，敬请期待")
 
+// ErrForbidden 越权操作（如删除别人的内容）
+var ErrForbidden = errors.New("无权操作")
+
 // Service 业务逻辑聚合，方法按领域分散在各文件
 type Service struct {
 	db      *gorm.DB